CVE-2026-43253

Summary

In the Linux kernel, the following vulnerability has been resolved:

iommu/amd: move wait_on_sem() out of spinlock

With iommu.strict=1, the existing completion wait path can cause soft lockups under stressed environment, as wait_on_sem() busy-waits under the spinlock with interrupts disabled.

Move the completion wait in iommu_completion_wait() out of the spinlock. wait_on_sem() only polls the hardware-updated cmd_sem and does not require iommu->lock, so holding the lock during the busy wait unnecessarily increases contention and extends the time with interrupts disabled.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux4bf5beef578e46393f11eb69dda7d17a065e05ff < f2f65b28d802a667119147444ec2ae33eebf9a58affected
LinuxLinux4bf5beef578e46393f11eb69dda7d17a065e05ff < 715c263119fd1b918a9fcbd8a36ea5b604a46324affected
LinuxLinux4bf5beef578e46393f11eb69dda7d17a065e05ff < e15768e68820142077bbca402d8e902f64ade1b0affected
LinuxLinux4bf5beef578e46393f11eb69dda7d17a065e05ff < 496269d12072ecb219826485bdbec70c92a8eef5affected
LinuxLinux4bf5beef578e46393f11eb69dda7d17a065e05ff < d2a0cac10597068567d336e85fa3cbdbe8ca62bfaffected
LinuxLinux4.9affected
LinuxLinux0 < 4.9unaffected
LinuxLinux6.6.128 <= 6.6.*unaffected
LinuxLinux6.12.75 <= 6.12.*unaffected
LinuxLinux6.18.16 <= 6.18.*unaffected
LinuxLinux6.19.6 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References